please help id mandarin variety

[sanitarium]

I bought this tree last year but the variety name was missing:/ not sure if it will be ever possible to id the correct variety?

thank you for any guess

here are some pics of fruit:

[Axier]

Can you see any colors on trunk and rootstock?
In Spain is very usual to paint citrus plants for identification, all nurseries use the same color codes.
If you tell me what colors have it, maybe I can tell you what variety it is.

[sanitarium]

Thanks Axier!

Here is what I found on trunk...

[Axier]

Ok Daniel, according to colors, you have an Ortanique mandarin (tangor) grafted on Volkameriana.
Don't surprise for the rootstock, I know that nursery, in fact I have several orange plants from them. They frequently use Volkameriana and macrophylla when sell for retail nurseries, they consider those citrus like ornamental plants, and volkameriana produces green and vigorous plants, but not the best fruits.
The color codes for citrus is a governmental rule and it is mandatory in Spain, so all nurseries use the same codes. The identification is 100 % sure.

By the way, it is an excellent juice mandarin, you can fill a glass with just two mandarins and the juice is delicious.
Spanish Ortaniques are now in grocery stores and they are incredibly sweet.

It is a late mandarin, it needs a long season for ripening.

If you want to get the sweetest Ortaniques, I would graft on a better rootstock: Carrizo, C35, Poncirus Trifoliata, Flying Dragon.

[sanitarium]

Wow thank you very much for complex report and mainly for the right identification! I was really hopeless and thinks that I will never find out the right variety.

Little disapointment for the rootstock Volkameriana, I have to say I have very little knowledge about the citrus rootstocks and their effects..
The tree is quite big and starting it again on new young rootstock (here we have lack of old rootstocks, comonly here are grafting done on  few years old poncius seedlings) is little frustating..
How bad is the rootstock? or better do you know how much is the taste declined by this type of rootstock?

thank you 

[Axier]

There is a lot of information out there regarding citrus rootstocks.
Usually, volkameriana is used for lemons, mainly Eureka, because citranges, trifoliates and macrophylla are incompatible with it.
It is said that volkameriana produces fruits with less soluble solids than trifoliates, this is not a problem with lemons, but it is when it comes to mandarins and oranges.
In any case, the differences are not astronomic, you also can crop decent fruits with volkameriana.

[sanitarium]

Thank you

yes there is some info on web, but I found only that the fruit is inferior/poor quality on this rootstock so was wondering how bad it is..
I have asked as you have much more real experiences.. and it is more valuable then any website

there is one more thing I found about volkameriana, that it is not very cold tolerant. how much is this quote right?

from what I know the mandarins are more cold tolerant then lemons..   

[Axier]

Volkameriana -6º C  (21-F)
Manadarins -6º to -8º C (it depends on variety) (21 to 18-F)
Satsumas -10º C  (14-F)
Lemons -4º C (it depends on variety) (25-F)